Microsoft Teams Viewing Participants

Hi there, When sharing a screen in Microsoft Teams you used to be able to see participants big if you clicked on their picture and I would then be able to see participants in large gallery big, now I can only see the PowerPoint big and participants at the top or side of my screen? I would really like to see students and their work? Does anyone know how I can achieve this. Why change this I was just getting used to the other way of view participants